As the continuously variable transmission for an automobile, a device which includes, as shown in FIG. 12, a drive pulley 2 having a fixed sheave 2a and a movable sheave 2b and provided at an engine side, a driven pulley 3 having a fixed sheave 3b and a movable sheave 3a and provided at a drive wheel side, and an endless power transmission chain 1 suspended between both the drive pulley and the driven pulley has been known. In this device, the movable sheaves 2b, 3a are moved close to or away from the fixed sheaves 2a, 3b, whereby the chain 1 is clamped with hydraulic pressure, and a contact load is generated between the pulleys 2, 3 and the chain 1 with a clamping force on this occasion, thereby to transmit a torque with a friction force in a contact part.
As the power transmission chain, there is disclosed in Patent Document 1, a power transmission chain including a plurality of links respectively having front and rear insertion parts into which pins are inserted, a plurality of first pins and a plurality of second pins for connecting the links which are arranged in a lateral direction of the chain, such that the front insertion part of one of the links is opposed to the rear insertion part of the other link so that the links can be flexed with respect to each other in a longitudinal direction. In this power transmission chain, the first pin which is fixed to the front insertion part of the one link and movably fitted into the rear insertion part of the other link and the second pin which is movably fitted into the front insertion part of the one link and fixed to the rear insertion part of the other link are relatively moved in rolling contact with each other, whereby the links can be flexed with respect to each other in the longitudinal direction. In this Patent Document 1, it is proposed to provide two or more types of pitch lengths of the links, shapes of rolling contact faces of the pins, contact positions of the pins with respect to a pulley face (offset amounts), and so on, for the purpose of reducing noise and vibration.    Patent Document 1: Japanese Patent Publication No. JP-A-2006-097844